iOS and iPadOS

The iOS SDK provides all the types and classes made available by Apple for creating applications for iPhone, iPad and iPod touch.

Each Cocoa SDK is spread over several frameworks and core include files. The core C APIs are located in rtl.fx, which is a package containing pretty much everything defined in /usr/include. The base framework of core Cocoa classes is called "Foundation" (shared with macOS), and contains, among many other things, NSObject, the base type for all Cocoa classes.

More frameworks are shared across sub-platforms, while each sub-platform also provides its own unique frameworks.

Please refer to the Introduction to the Frameworks topic for more information on how the frameworks fit together, and how they differ between the (currently) four separate Cocoa platforms.

For all the SDK frameworks, the Namespace used matches the framework name.

iOS is built on the same core operating system as macOS, and shares many of the lower-level non-UI frameworks wth it. It provides its own paradigms for GUI development, in UIKit and related frameworks.